Test apparatus, system, and method having a magnetic feature

ABSTRACT

A test apparatus involving a rotor coupled to a drive shaft, wherein the drive shaft is mechanically coupled to a drive system; a stator coupled to a brush holder; a brush held by the brush holder, wherein the brush is held in contact with the rotor; a housing for supporting the rotor and the stator; and a superconducting magnet for providing a magnetic field in the vicinity of the brush, in accordance with one embodiment.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This document is a continuation application that is related to, andclaims priority from U.S. patent application Ser. No. 11/549,587,entitled “Test Apparatus, System, and Method With a Magnetic Feature,”and filed on Oct. 13, 2006, which is commonly owned, and which is herebyincorporated by this reference in its entirety.

GOVERNMENT RIGHTS

The present invention was made with support of the government underOffice of Naval Research, Contract No. N00014-04-C-0618. The Governmentmay have certain rights in the present invention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a test apparatus for testing a brushand a brush holder. More specifically, the present invention relates toa test apparatus for testing brushes and brush holders in the presenceof a magnetic field.

2. Discussion of the Related Art

Evaluation of multi-conductor metallic brushes for electric propulsionmotors and generators is important in assuring reliable operation of themotors, generators, vehicles, or vessels with which they are utilized.The complex operational environment of a large number of brushes can besimulated by a computer program; however, preferable is that thecomputer results be validated by laboratory testing. Additionally,brushes can be evaluated after being actually used in a motor; however,these brushes are not easily accessible. Furthermore, in many instances,disassembling the motor during use in order to evaluate the brushes isimpractical. Previously, brushes have been evaluated using a testapparatus that includes a motor driven rotor. The brushes are held incontact with the rotor; and the wear on the brushes can be evaluated.However, this type of test apparatus lacks many real world applications.

Motors and generators can be subjected to high magnetic field strengthsand varying environmental conditions while in use. These high varyingmagnetic fields and varying environmental conditions, possibly presentin electric propulsion motors and generators, create a need for anapparatus to simulate the conditions of the motors and generators. Thus,a need exists for a measurement apparatus that can test brushes andbrush holders under varying magnetic fields as well as varyingenvironmental conditions.

SUMMARY OF THE INVENTION

The present embodiments provide a test apparatus, system, and method fortesting many brushes and brush holders under a varying magnetic field aswell as a plurality of varying environmental conditions. The presenttest apparatus for testing a plurality of brushes and brush holdersunder a varying magnetic field can be used with measurement instrumentsto evaluate the performance of the brushes and brush holders withincontrolled operating conditions.

One embodiment can be characterized as a test apparatus, comprising arotor coupled to a drive shaft, wherein the drive shaft is mechanicallycoupled to a drive system. The apparatus comprises a stator coupled toat least one brush holder and at least one brush held by the at leastone brush holder, wherein the at least one brush is held in contact withthe rotor. The test apparatus system further comprises a housing forsupporting the rotor and the stator as well as a magnet for providing amagnetic field in the vicinity of the at least one brush.

The present invention also involves a test system, comprising anapparatus for testing a plurality of brushes and a plurality of brushholders under a varying magnetic field. The test apparatus comprises astator, at least one brush holder coupled to the stator, at least onebrush held by the at least one brush holder, a rotor positioned tocontact the at least one brush, a drive shaft coupled to the rotor, anda magnet for supplying a magnetic field, wherein the at least one brushcontacts the rotor. The test apparatus system further comprises a drivesystem coupled to the drive shaft, a power supply for providing power tothe at least one brush, and a power supply for providing power to themagnet.

Another subsequent embodiment can be characterized as a method oftesting at least one brush and at least one brush holder, the methodcomprising rotating a rotor of a test apparatus, providing power from abrush power supply to at least one brush in contact with the rotor,providing power from a magnet power supply to a magnet, and generating amagnetic field from the magnet in the vicinity of the at least one brushand the rotor.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the presentinvention will be more apparent from the following more particulardescription thereof, presented in conjunction with the followingdrawings.

FIG. 1 is a front perspective diagram of a test apparatus, in accordancewith an embodiment of the present invention.

FIG. 2 is a rear perspective diagram of the test apparatus, as shown inFIG. 1, in accordance with an embodiment of the present invention.

FIG. 3 is a front view diagram of the test apparatus, shown in FIG. 1,in accordance with an embodiment of the present invention.

FIG. 4 is a side cross-sectional diagram of the test apparatus, as shownin FIG. 1, in accordance with an embodiment of the present invention.

FIG. 5 is a schematic diagram of a test system, comprising a testapparatus, in accordance with an embodiment of the present invention.

Corresponding reference characters indicate corresponding componentsthroughout the several views of the drawings. Skilled artisans willappreciate that elements in the figures are illustrated for simplicityand clarity and have not necessarily been drawn to scale. For example,the dimensions, sizing, and/or relative placement of some of theelements in the figures may be exaggerated relative to other elements tohelp to improve understanding of various embodiments of the presentinvention. Also, common but well-understood elements that are useful ornecessary in a commercially feasible embodiment are often not depictedin order to facilitate a less obstructed view of these variousembodiments of the present invention. Also understood is that the termsand expressions used herein have the ordinary meanings as are usuallyaccorded to such terms and expressions by those skilled in thecorresponding respective areas of inquiry and study, except where otherspecific meanings have otherwise been herein set forth.

DETAILED DESCRIPTION

The following description is not to be taken in a limiting sense, but ismade merely for the purpose of describing the general principles of theinvention. The scope of the invention should be determined withreference to the herein appended claims. The present embodiments addressthe problems described in the background while also addressing otheradditional problems as will be seen from the following detaileddescription.

The embodiments described herein provide an apparatus for testingbrushes in a variety of different conditions. The brushes can besubjected to a magnetic field, such as would be present in real-worldapplications. Because the brushes of homopolar machines can be thegreatest source of failure, the capability of testing various brushesunder a variety of different conditions is advantageous. Additionally,some embodiments provide the ability to test and measure the brushperformance under many different environmental situations. The long termevaluation of brushes under typical motor operating conditions can bemonitored in order to improve wear rate, current density, efficiency,and reliability. Additionally, the interactions between the brushes andthe rotor contact surface can be evaluated.

Advantageously, in some embodiments, both magnetic field components(B_(r) and 13 _(z)) can be adjusted in the vicinity of the brushes andbrush holders. In various embodiments, the brushes can be evaluated overa large variation in the disc surface speed. Additionally, the brushescan be evaluated with different additives at the interface between thebrush and the rotor. The brushes can also be evaluated for losses due toOhmic heating resulting from transfer and circulating currents, as wellas for mechanical losses resulting from friction. The long termperformance of the brushes can be evaluated based upon the azimuthallocation of the brush and holder as well as the effect of wear due toparticle accumulation in long term performance.

Advantageously, the evaluation of the brushes under different ranges ofcoverage factors can be performed. Additionally, the thermal limits andoperational envelope of the brushes and the brush holders can beevaluated. Different brush designs and the evaluation of brushes underdifferent duty cycles can be evaluated. The validation of parametersfrom both a microscopic analysis and a macroscopic analysis as well asmodeling can be performed. Furthermore, the accumulation of data tosupport statistical analysis for the projection of a lifetime for thebrushes can be accomplished for a large number of brushes.Advantageously, the test apparatus, in some embodiments, can be operatedunattended, twenty-four hours per day, for extended periods of time.

The above features can be accomplished in various embodiments of theapparatus described herein. The following description of a testapparatus, system, and method in accordance with various embodimentswill further describe and detail the above features.

Referring now to FIG. 1, a front perspective diagram illustrates a testapparatus 100, in accordance with an embodiment of the presentinvention. Shown is a rotor 102, a stator 104, a set of brushes 106, abrush holder 108, a machine housing 110, a support structure 112, adrive system 114, a plurality of gas delivery tubes 116, a plurality ofconnectors for a data acquisition system 118, a plurality of powersupply connectors 120, a magnet power supply connector 122, acryo-cooler, e.g., a cryo-compressor 124, an environmental chamberhousing 126, a support ring 128, and a plurality of attachment clips130, by example only. An environmental delivery system supplies gas tothe environmental chamber 126. The plurality of power supply connectors120 comprises first and second power supply connectors.

The brush holder 108 is connected to the stator 104 and holds thebrushes 106 in contact with the rotor 102. The rotor 102 and stator 104are held in place by the machine housing 110 and the support structure112. This embodiment includes only one brush holder 108; however, aplurality of brush holders can be connected to the stator 104. Theplurality of gas delivery tubes 116 are coupled to the brush holders andsupply gas, e.g., carbon dioxide, that controls the pressure that thebrushes 106 exert in contacting the rotor 102. In this embodiment, theapparatus comprises two brushes 106 and one brush holder 108; however,understood is that many brushes and brush holders may be placed aroundthe stator in other embodiments. Additionally, the brushes and brushholders are placed on both an inner side and an outer side of the statorin some embodiments (see FIG. 4). The present test apparatus is capableof testing up to one hundred twenty brushes at one time. In order tohold one hundred twenty brushes, twenty brush holders are disposed onthe outside of the stator 104; and twenty brush holders are disposed onthe inside of the stator 104 (see FIG. 4). Each brush holder can beconfigured to hold a plurality of brushes. Thus, in the embodimentshown, when the test apparatus 100 is fully loaded, 120 brushes arebeing tested simultaneously.

The plurality of power supply connectors 120 are generally coupled to apower supply (not shown). The power supply supplies power to the testapparatus and controls the current flowing from the stator, through thebrushes, and into the rotor. The drive system 114 (shown in more detailin FIG. 3) is used to rotate the rotor 102 as current flows through thebrushes 106. Additionally, a magnetic field is produced by a magnet(shown in FIG. 4) such that the brushes 106 are subjected to a magneticfield. The magnetic field simulates the environment to which the brusheswould be subjected in a motor in operation. The magnet, which canproduce magnetic fields over a range of strengths, is powered by amagnet power supply. The magnet power supply is coupled to the magnetthrough the magnet power supply connector 122. The cryo-cooler, e.g.,cryo-compressor 124 cools the magnet. In one embodiment, the magnet is asuper-conducting magnet that operates at approximately 4.2 degreesKelvin. The magnet produces a magnetic field when charged by the powersupply. The strength of the field varies depending upon the level ofcharge of the magnet. In one embodiment, the proportion of the axial andradial portions of the magnetic filed (B_(z) and B_(r)) in the brushoperating region are controlled by varying the charge of the magnet andby adjusting the axial position of the rotor 102 and brushes 106relative to the magnet.

The environmental chamber housing 126 is attached to the front of themachine housing. The environmental chamber housing 126 encloses therotor 102, the stator 104, and the brushes 106 inside of anenvironmentally controlled chamber. The environmental chamber housing126 comprises, in the exemplary embodiment, the support ring 128, theplurality of attachment clips 130, and a front plate. The front plate ismade from, for example, glass or plastic, and is preferably lighttransmissive, such that the brushes can be viewed during operation. Theenvironmental chamber housing 126 allows for the brushes to be testedunder a variety of different environmental conditions, such as withdifferent temperatures and different gasses. Because the front plate isgenerally made from a transmissive material, it is not shown in thefigure; however, the front plate forms a seal on the inside of thesupport ring.

Referring to FIG. 2, a rear perspective diagram illustrates a testapparatus, as shown in FIG. 1, in accordance with an embodiment of thepresent invention. Shown is the machine housing 110, the supportstructure 112, the drive system 114, the plurality of connectors for thedata acquisition system 118, the plurality of power supply connectors120, the magnet power supply connector 122, the cryo-cooler, e.g., acryo-compressor 124, a drive belt 132, a drive shaft 134, and a waterunion 136.

The drive system 114 is coupled to the drive shaft 134 through the drivebelt 132. The drive system 114 rotates the drive shaft 134 of the testapparatus 100 in a controlled manner. The drive system 114, in oneembodiment, is a variable frequency controlled electric motor and drivebelt system that can produce a rotor speed of up to 30 m/s. Because thetest apparatus 100 includes the drive shaft 134 and, additionally, themagnet, the test apparatus is not a true motor. As described above, themagnets are charged as the rotor 102 is rotated and current is driventhrough the brushes 106. This creates torque which must be compensatedby the drive system 114. Thus, a balance exists between the drive system114 and the magnet that is taken into account when operating the testapparatus 100. Generally, in a motor, the rotor has many windings thatcreate a large amount of torque; however, the present embodiment of thetest apparatus 100 only includes one winding, thereby reducing thegenerated torque.

As described, in one embodiment, the drive system 114 is a variablefrequency drive (VFD) that is used to control the speed of the rotor102. The VFD controls the speed of the motor that, in turn, drives therotor 102. In operation, the VFD will maintain a constant revolutionsper minute (RPM) of the rotor. The current passing through the brushesand rotor 102 in the magnetic field generated by the magnet will eitheradd torque or reduce torque on the rotor 102, i.e., either try toaccelerate the rotor or brake the rotor. If the current is trying toaccelerate the rotor 102, the VFD must provide braking torque tomaintain a constant RPM of the rotor. If the current is trying todecelerate the rotor, the VFD will provide additional torque to maintainthe constant RPM of the rotor. In one embodiment, the VFD is acommercially available unit with an internal chopper to allowdissipation of braking energy. The energy is dissipated into anexternal, water cooled, braking resistor. The VFD settings may be madeat the front panel of the VFD or remotely via an Ethernet port. TheEthernet port also allows for remote monitoring of the status of theVFD.

A water cooling system is connected to the water union 136. The watercooling system is a controllable cooling system for the rotor 102 andstator 104. This allows the brushes to be tested at varying degrees ofoperation and also prevents the rotor 102 and the stator 104 fromoverheating. Water is supplied to the water union 136 through waterhoses (not shown). The water union 136 is designed such that the driveshaft 134 can rotate while the water union 136 remains in place. In oneembodiment, the water union 136 is a hydraulic rotary union mounted tothe end of the drive shaft 134 which passes water down holes in thedrive shaft 134 and into the slip rings. Supply and return hoses fromthe cooling water system connect to the hydraulic rotary union and alsoto plumbing connected to the stator bus bars.

Referring to FIG. 3, a front view diagram illustrates the testapparatus, as shown in FIG. 1, in accordance with an embodiment of thepresent invention. Shown are the rotor 102, the stator 104, the brushes106, the brush holder 108, the support structure 112, the plurality ofgas delivery tubes 116, and the environmental chamber housing 126.

The stator 104 is divided into four sections. Each section can hold upto five brush holders. The plurality of gas delivery tubes 116 supplygases to a respective plurality of brush holders, thereby controllingthe pressure that the brushes 106 exert on the rotor 102. In oneembodiment, the rotor 102 is an electrically-shorted double slip ringmounted onto a stainless steal wheel and shaft. Each section of thestator 104 comprises two stacked copper bus bars mounted to a back plate(shown in FIG. 4).

Referring to FIG. 4, a cross-sectional diagram illustrates the testapparatus, as shown in FIG. 1, in accordance with an embodiment of thepresent invention. Shown is the rotor 102, the stator 104, a first brush140, a second brush 142, a first brush holder 144, a second brush holder146, a first bus bar 147, a second bus bar 148, a back plate 150, themachine housing 110, the support structure 112, the drive system 114,the drive belt 132, the plurality of gas delivery tubes 116, a magnet152, a magnet housing 154, the drive shaft 134, the water union 136, afirst bearing 155, a second bearing 156, a center chamber 158, a gasdelivery attachment 150, and the environmental chamber housing 126.

The first brush 140 is held by the first brush holder 144; and thesecond brush 142 is held by the second brush holder 146. The first brushholder 144 is connected to the first bus bar 147 on a front side of thestator 104; and the second brush holder is connected to the second busbar 148 on a back side of the stator 104. As described above, the brushholders 142, 144 can be attached to either the front side or the backside of the stator 104, thus allowing for greater capacity to test thebrushes 106.

The center chamber 158 and the gas delivery attachment 160 allow for thedelivery of environmental gases into vicinity of the brushes 106, therotor 102, and the stator 104. The environmental chamber housing 126(described above in relation to FIG. 1), disposed on the front of thetest apparatus 100, maintains the gas at the front of the test apparatus100. This allows the brushes 106 to be tested while in the presence ofdifferent types of environmental gases and varies pressure within thechamber 158. The environmental chamber housing 126, in one embodiment,encloses the stator 104, the rotor 102, and the brushes 106. Theenvironmental chamber housing 126 is sealed and various gaseousatmospheres, as delivered by an environmental control system, can betested.

The magnet housing 154, in one embodiment, is a vacuum-sealed,super-cooling chamber for a superconducting magnet. The superconductingmagnet is cooled by the cyro-compressor 124. The superconducting magnetcan generate large magnetic fields in the vicinity of the brushes 106,thus allowing for the testing of the brushes 106 under conditions thatsimulate the real operation of motors.

The drive shaft 134 is supported by the first bearing 154 and the secondbearing 156. In one embodiment, the first bearing 154 and the secondbearing 156 are rolling element bearings. The bearings 154, 156 allowthe drive shaft 134 to easily rotate. The drive shaft 134 is coupled tothe rotor 102, thus as the drive motor is on the drive belt 132 rotatesthe drive shaft 134 which in turn rotates the rotor 102. Additionally,during operation, the magnet 152 generates a magnetic field in thevicinity of the first brush 140 and the second brush 142. The rotor 102,the stator 104, and the brushes can be adjusted in an axial direction ofthe shaft by adjusting the position of the drive shaft 134. That is, therelative axial position of the brushes 106 in relation to the magnet 152is adjustable. This adjustment allows for control over both the axialand radial components of the magnetic field (B_(z) and B_(r)) in thevicinity of the brushes 106, thus allowing for a more controlledenvironment for testing.

The stator 104 is connected to the back plate 150 which is mounted tothe machine housing 110. The first bus bar 147 and the second bus bar148 can be easily accessed and allow for the relatively simple removaland replacement of the brush holders 144, 146 and/or brushes 106. Asdescribed above, in one embodiment, the stator 104 comprises foursections where each section includes two stacked bus bars mounted to theback plate 150. The bus bars line up with the two rings of the doublecopper slip ring of the rotor 102. The brush holders 144, 146 aremounted to the bus bars and the brushes 106 are then in contact with therotor slip rings. The two bus bars are electrically isolated from eachother and from the back plate 150.

Referring to FIG. 5, a schematic diagram illustrates a test system, inaccordance with an embodiment of the present invention. Shown is a testapparatus 500, a control system 502, a brush power supply 504, acyro-cooler 506, a cooling system or chiller 508, a magnet power supply510, and a data acquisition system 512, a gas supply system 514, anenvironmental control system 516, and a drive motor 518.

The control system 502, in one embodiment, controls the operation of theentire system, including the test apparatus 500, the magnet power supply510, the brush power supply 504, the chiller 508, the environmentalcontrol system 516, the cyro-cooler 506, the gas supply system 514, andthe data acquisition system 512. In an alternative embodiment, at leastone or more of the individual components of the system are operatedindependently of the control system 502. For example, the dataacquisition system 512 can be operated independently from the controlsystem 502. The brush power supply 504 is connected to the testapparatus 500 and supplies current to the brushes 106. the rotor 102,and the stator 104 during operation. In one embodiment, the brush powersupply 504 is a constant-current supply used to provide the current fortesting the brushes 106. The brush power supply 504 is capable ofproviding up to 6,000 amps dc at up to 5 volts. The brush supply is alow ripple supply (<1% pk-pk of full current) even at low voltage. Thebrush power supply 504 consists of two commercial supplies, each ratedat 3,000 amps, bused together in parallel. “Freewheeling” diodes provideprotection for the brush power supply 504 from the back EMF that can begenerated by the movement of the rotor 102 in the magnetic field. Thebrush power supply 504 utilizes a master-slave configuration where themaster settings are used to control both supplies. A DC power supplycapable of delivering up to 26,000 Amps at 10 Volts may be connected tothe stator bus bars. The current path delivered by the brush powersupply 504 is through one stator bus bar, through the brush holders 144,146 and brushes 106 into the rotor slip ring, through the rotor 102 intothe second slip ring, and out of the second slip ring through brushes106 and brush holders 144, 146 mounted to the second bus bar.

The magnet power supply 510 supplies power to the magnet duringoperation in order to induce a magnetic field in the vicinity of thebrushes 106. The cyro-cooler 506 cools the magnet during operation. Asdescribed above, in one embodiment, the magnet is a superconductingmagnet that is cooled to 4.2 degrees Kelvin. The gas supply system 514provides gas to the brush holders 144, 146 which, in turn, control thepressure that the brushes 106 exert on the rotor 102. The chiller 508provides cooling for the rotor 102 and stator 104 during operation. Thedrive motor 518 is, for example, a variable frequency motor that iscoupled to the shaft through a drive belt. The drive motor 518 turns theshaft which then turns the rotor 102 during operation.

The environmental control system 516 supplies environmental gases to theenvironmental chamber of the test apparatus 500. This allows the brushes106 to be tested under different pressure and environmental conditions.The data acquisition system 512 is connected to the test apparatus 500and collects data about the temperature and pressure, e.g., temperaturedata and pressure data, within the environmental chamber of the testapparatus 500. The data acquisition system 512, in one embodiment, is astandard system including sensors and data logging equipment, such as, acomputer system. The data acquisition system 512, in one embodiment, isconnected to sensors designed to measure temperature, voltage drop,brush wear, humidity, oxygen concentration, pressure, speed, and manyother parameters at various points. In particular, stator bus bar, brushholder 144, 146, brush 106, and rotor slip ring temperatures aremeasured. In one embodiment, up to 175 channels are allocated forinstrumentation with the majority of the measurement signals beingrecorded on by the data acquisition system 512.

Information as herein shown and described in detail is fully capable ofattaining the above-described object of the invention, the presentlypreferred embodiment of the invention, and is, thus, representative ofthe subject matter which is broadly contemplated by the presentinvention. The scope of the present invention fully encompasses otherembodiments which may become obvious to those skilled in the art, and isto be limited, accordingly, by nothing other than the appended claims,wherein reference to an element in the singular is not intended to mean“one and only one” unless explicitly so stated, but rather “one ormore.” All structural and functional equivalents to the elements of theabove-described preferred embodiment and additional embodiments that areknown to those of ordinary skill in the art are hereby expresslyincorporated by reference and are intended to be encompassed by thepresent claims.

Moreover, no requirement exists for a device or method to address eachand every problem sought to be resolved by the present invention, forsuch to be encompassed by the present claims. Furthermore, no element,component, or method step in the present disclosure is intended to bededicated to the public regardless of whether the element, component, ormethod step is explicitly recited in the claims. However, that variouschanges and modifications in form, material, and fabrication materialdetail may be made, without departing from the spirit and scope of theinvention as set forth in the appended claims, should be readilyapparent to those of ordinary skill in the art.

1. A test apparatus, comprising: a rotor coupled to a drive shaft,wherein the drive shaft is mechanically coupled to a drive system; astator coupled to at least one brush holder; at least one brush held bythe at least one brush holder, wherein the at least one brush is held incontact with the rotor; a housing for supporting the rotor and thestator; and a superconducting magnet for providing a magnetic field in avicinity of the at least one brush.
 2. The apparatus of claim 1, furthercomprising at least one gas delivery tube to supplies gas to the atleast one brush holder for controlling a pressure that the at least onebrush exerts on the rotor.
 3. The apparatus of claim 1, furthercomprising an environmental chamber enclosing the rotor and the at leastone brush.
 4. The apparatus of claim 3, further comprising at least onedata acquisition system.
 5. The apparatus of claim 1, furthercomprising: a first power supply connector for supplying power to the atleast one brush; and a second power supply connector for supplying powerto the superconducting magnet.
 6. The apparatus of claim 1, furthercomprising a magnet housing for accommodating the superconductingmagnet, wherein the magnet housing comprises a vacuum-sealedsuper-cooling housing.
 7. The apparatus of claim 1, wherein the drivesystem comprises a motor and drive belt coupled to the drive shaft. 8.The apparatus of claim 1, further comprising a support structure forsupporting the housing, the stator, the rotor, and the drive shaft.
 9. Atest system, comprising: a test apparatus, the apparatus comprising: astator; at least one brush holder coupled to the stator; at least onebrush held by the at least one brush holder; a rotor positioned tocontact the at least one brush; a drive shaft coupled to the rotor; anda superconducting magnet for supplying a magnetic field to a location atwhich the at least one brush contacts the rotor; a drive system coupledto the drive shaft; a power supply for providing power to the at leastone brush; and a power supply for providing power to the superconductingmagnet.
 10. The system of claim 9, further comprising an environmentalchamber enclosing the rotor and the at least one brush.
 11. The systemof claim 10, further comprising a data acquisition system coupled to thetest apparatus.
 12. The system of claim 10, further comprising anenvironmental delivery system for supplying gas to the environmentalchamber.
 13. The system of claim 9, further comprising a gas deliverysystem for supplying gas to the at least one brush holder.
 14. Thesystem of claim 9, further comprising a chiller coupled to the testapparatus for controlling a temperature of the rotor and the at leastone brush.
 15. The system of claim 9, further comprising a magnethousing, wherein the magnet housing is a vacuum-sealed super-coolinghousing for the superconducting magnet.
 16. The system of claim 15,further comprising a cryo-cooler for cooling the superconducting magnet.17. A method of testing at least one brush, comprising: rotating a rotorof a test apparatus; providing power from a brush power supply to atleast one brush in contact with the rotor; providing power from a magnetpower supply to a superconducting magnet; and generating a magneticfield from the superconducting magnet in a vicinity of the at least onebrush and the rotor.
 18. The method of claim 17, further comprisingacquiring data related to an operation of the at least one brush. 19.The method of claim 18, further comprising providing gas to anenvironmental chamber enclosing the rotor and the at least one brush.20. The method of claim 19, further comprising acquiring at least one oftemperature data and pressure data within the environmental chamber.